Means of fabricating wall sections and the like



June a, 1943. o, BERGSTRQM 2,321,174

MEANS OF FABRICATING WALL SECTIONS AND THE LIK Filed April 24, 1941 Patented June 8, 1943 B'KEANS OF FABRICATING WALL SECTIONS AND THE LIKE.

Oscar Bergstrom,

Evanston, Handy Manufacturing Company,

a corporation of Illinois Application April 24, 1941, Serial No. 330,156

1 Claim.

This invention relates to improvements in fabricating wall sections and the like, and in particular to an improved method of and apparatus for joining panels of wall board in end to end relationship so as to fabricate a wall section.

Wall board such as plywood or a resin impregnated composition board is commercially available in panels, the size of which is considerably less than the size of the wall sections to be fabricated therefrom. These panels when used separately must be secured to suitable studding and the joint between them taped or filled before they are in condition to receive any decorative finish. In many instances it is preferable to secure these panels together into an integral wall section, and then to apply the section as a whole to the studding.

An object of my invention is to provide an improved method of joining panels of wall board to each other.

A further object is to provide an improved apparatus for fabricating a wall section.

A further object is to provide an improved method of and apparatus for adhesively securing separate panels of wall board to each other in such a manner that the joint is almost imperceptible to the eye.

Another and important object is to provide an improved method of and apparatus for permanently fabricating a wall section, as described. in but a very small portion of the time required for fabrication by prior methods and apparatus.

Still another object is to provide an improved apparatus of simple construction and economical in operation for holding two panels of wall board in edge to edge pressure relationship while a sealing strip or integral overlap joint as Well as the abutting edges are adhesively bonded together.

More specifically this invention embodies means for holding two panels in pressure abutting relationship and applying a strip of like material to the butt joint formed thereby, after adhesi e has been applied to the abutting and overlapping parts, and applying heat and pressure in controlled amounts thereto.

With reference to the drawing in which like numerals denote like parts-- Fig. 1 is a side elevation of a preferred embodiment of the apparatus of my invention, a portion thereof being shown in section, this view being taken along line Il of Fig. 2

Fig. 2 is a front elevation of the apparatus shown in Fig. 1; and

Fig. 3 is a perspective view of a portion of a 111., assignor to Chicago, Ill.,

wall section such as may be fabricated by the method and apparatus of my invention.

Referring now to Fig. 1 and Fig. 2, reference numeral i0 indicates a suitable base which is provided with an upper plane surface, the base being suitably mounted on supporting rail ll. Feed table brackets 12 are secured to the base i!) and extend rearwardly thereof. Adjusting blocks M are associated with the brackets l2 and are engaged by worms iii. The worms are journalled in the forward ends of the brackets and in the upwardly extending rear edges ll thereof, the bracket being recessed to accommodate the worms. Hand wheels 15 are secured to the worms exteriorly of the upwardly extending edges ll of the brackets l2. It will be seen that as the hand wheels are rotated, the adjusting blocks l4 may be advanced so as to urge forwardly a panel of plywood, the rear edge of which is engaged by the blocks 14.

A top frame member i3 i mounted on pillars l8, and cylinders 28 and 2i are suspended from the top frame member 19. These cylinders may be of the type customarily employed in a pneumatically operated press. The usual piston rods 22 and 23 extend downwardly from the pistons (not shown) of the respective cylinders 20 and 2|. The piston rods are associated with each other by means of a spacing member 24 so that they will work in unison.

A pressure member 25 in the form of a transversely disposed beam is secured to the piston rods 22 and 23, and is adapted to be raised and lowered thereby. An electric hot plate, or shoe, 26 containing electrical heating elements I3 is carried by the pressure member 25 and is spaced away therefrom by means of spacers 21 so as to minimize loss of heat. The spacers preferably are of a heat insulating material. A control valve 29 is provided simultaneously to control the operation of the pneumatic cylinders 20 and 2|. Air pressure pipes 30 and 3! lead from the valve 29 to the cylinder 23 and 2| at points above their pistons to move the piston rods downwardly and to exhaust the air cylinders on upward strokes of the pistons. Other pipes 32 and 33 lead from the valve 29 to the cylinders 20 and 2| at points below their pistons in order to operate the press to lift the pressure member and to exhaust the air cylinders on downward movement of the pistons.

The operation of the valve 29 is controlled by a balanced hand lever 28 and a timing unit 34. lhe hand lever 28 when depressed to the position shown in the drawings operates the valve 29 to cause the flow of air in such manner as to lower the pressure member 25 with its hot plate 26 into pressure engagement with the work. Movement of the hand lever 28 upwardly from the position shown serves to reverse the flow and exhaust of air from the cylinders so as to cause the hot plate 26 to be elevated out or engagement with the work. Suitable power lines 35 lead into the timer, and a cable 36 extends between the timer and a solenoid coil 39 having its plunger coupled directly to the hand lever 28 of the valve 29. A cable feed line 63 also extends from the timing unit 34 through a thermostatic switch 31, which is mounted on the pressure member 25 to the electrical heating elements I3 of the hot plate 26. A thermostat 38 is mounted on the hot plate 26 and associated with the thermostatic switch 31.

The timing unit 34 may be set at control 64 for any prescribed time interval within a desired range following which interval a circuit is momentarily established through the cable 35 and the solenoid 39. Energization of the solenoid 38 elevates the balanced hand valve control lever 28 and opens the press. I have found that a time interval of substantially three minutes is sufficient to provide athoroughly bonded joint under the method herein described.

It will be seen therefore that the parts are so arranged that when the lever 28 is depressed, the valve 29 is opened to permit air to flow into the upper portions of the cylinders, thereby forcing the pressure member downwardly. As the hand lever 28 is moved downwardly as described a finger 56 carried by the plunger of the solenoid 39 engages a trip bar 65 associated with the tim ing unit to set the time switch in operation. After three minutes, the position of the valve is automatically changed by means of the timing unit 34 and solenoid 39 so as to cause the pressure member to be elevated. The pressure member remains in this elevated position until such time as the hand lever 28 for the valve 29 is again depressed. v

The base H) is adapted to receive two panels and 58 of plywood or other wall panel board which are disposed in abutting'relationship, the joint between the two being disposed beneath the electric hot plate 26. Thermosetting glue is applied to the abutting edges of the panels 51 and '58, and a gusset or a sealing strip 59 which has also been coated with such glue is disposed over the abutting edges. When the mechanism is set into operation by depression of the hand lever 28 the hot plate is pressed into contact with the sealing strip so as to securely join the parts to each other.

The adhesive which I prefer to use is a thermosetting or hot process glue and may be one of many such glues all having the property of be coming converted in the presence of heat, at predetermined temperatures, through a free flowing liquid or se1ni-plastic phase into a solid phase. The temperature of the electric hot plate is automatically maintained within the limits of 300 to 450 F., and the hot plate is urged against the joint preferably for a period of approximately three minutes although such time may be shortened or lengthened as desired to suit variations in panel material and adhesives. By automatically withdrawing the hot plate out of contact with the wall section at the expiration of this time, overheating of the plywood or composition is prevented and the apparatus is known to be in readiness for operation on another panel. The

hot plate is urged into contact with the wall section with a pressure of between thirty to sixty pounds per square inch. This pressure causes the thermo-setting glue to be forced into the fibers of the panels so as to thoroughly impregnate the same and also to bring the fibers of the panels and of the sealing strip into intimate contact with each other, thereby securing an exceedingly tight and secure joint.

To prevent buckling of the panel during the application of edgewise pressure a shaft 4! is mounted with respect to the top frame member I9 by means of journals 40, the shaft being provided with a plurality of arms 42. Vertically disposed rods 43 are associated with the arms 42 and carry pressure members 44 which are in the form of inverted channels. A bracket 45 is secured to one end of the top frame member I 8 and is provided with a screw 45 which extends therethrough. A hand wheel 41 is secured to the upper end of the screw, and a bearing member as is provided at the lower end thereof. The bearing member is adapted to engage an arm 49 which extends rearwardly of the shaft 4!.

The brackets [2 are provided with flanges 50 which are laterally disposed at either side of the worms l5. The flanges are all disposed in a common plane and serve to support the panel 51. The flanges 5| of the channeled pressure members 44 are disposed immediately above their corresponding flanges 50.

It will be seen that by manipulation of the hand wheel 47, the pressure members 44 can be urged downwardly to securely hold the panel 51 against the'brackets H2. The hand wheels I5 may then be manipulated to urge the panel 51' forwardly at a plurality of points so that the abutting edges 6! thereof will be urged into intimate pressure contact with the edge 62 of the panel 55. The pressure members 44 serve to prevent the panel 51 from buckling when the ad- Justing blocks I 4 are brought into contact with the panel. By using a plurality of adjusting blocks, contact may be maintained between the abutting edges SI and 62 for their full length. l

The panel 58 is'held in position by means of the pressure member 52 which is mounted on screws 53. These screws operate in screw bearings 54 which are secured to the upper frame member I 9. Hand wheels 55are provided for the screws 53 so that the pressure member 52 may be conveniently lowered and raised into and out of operative position.

In operation it will be seen that after the thermo-setting glue has been applied to the abutting edges 6| and 62 of the panels, and to the sealing strip 59, that these parts are then placed in posi-- tion on the base I 0. The panel 53 is first secured in its position by means of the pressure member 52, and then the panel 51 is urged against the panel 58 in abutting relationship vby means of the adjusting blocks I4, the pressure members 44 being first brought into operative engagement with the panel 51 to prevent buckling thereof.

The lever 28 is then depressed and the parts which are being held under lateral pressuieare now subjected to vertical pressure, and are at the same time heated at a predetermined temperature for a predetermined time. The hot plate 26 is automatically withdrawn from contact with the wall section and the same may then be released by manipulation of the hand wheels 55 and 41. The wall section is then advanced, and another panel is put in place to be joined thereto.

The adhesive may be applied to the parts either by brushing or it may be applied in the form of a membrane or strip. Because of the fact that the abutting edges of the panels are laterally forced against each other, and are also forced against a. co-planar supporting surface, during the time that the adhesive is penetrating the fibers of the parts and bonding the parts together, the joint, as viewed from the flush side of the panel, is coextensive with the adjacent surfaces. If an excess of adhesive has been applied and has worked through and spread itself on the flush side, it may be sanded off. I have found that the joint, formed in accordance with my invention, resists bending stresses to a greater extent than the central portions of the panels, and any fracturing of the wall section will occur at the latter portions rather than at the joint.

Obviously while I have herein described the application of my invention to the joining of abutting edges of panels by means of an overlapping gusset, the process and the apparatus therefore may just as efliciently be used with panels, whereof the edges are cut to provide overlap or scarf joints, without the use of gussets. Furthermore, instead of actuating the pressure memher 25 by a pneumatic press, a hydraulic press or a manually operated screw press may be employed.

Although I have shown only a preferred embodiment of my invention, it will be understood that numerous modifications and changes may be made therein without departing from the spirit of my invention. This invention is limited only by the following claim.

Apparatus for joining two panels of wall board together comprising means to hold said panels in edge abutting relationship, and means to urge a gusset against said abutting edges, said means comprising a hot plate adapted to overlie said gusset, pneumatically operated press means to urge said hot plate against said gusset, and means for controlling the operation of said press means, said control means including a valve adapted for manual operation in one direction together with automatic means for operating said valve in the other direction, and timing means for the control of said automatic valve operating means whereby said hot plate will be removed from contact with said gusset after a predetermined period of time.

OSCAR BERGSTROM. 

